1. Field of Invention
The present invention relates to a content delivery network system and a building method for the same, and, more particularly, to a network system, in which the speed of content delivery over the Internet is fastened by using the characteristics of VPN (Virtual Private Network) and BGP (Border Gateway Protocol). The network system built by the present invention has the function of collecting data. The network system building method of the present invention can be utilized by general networks.
2. Description of Prior Art
For an individual and autonomous network, the building of network nodes needs private routes for accessing. Typically, an ISP (Internet Service Provider) uses the communication network provided by a telecommunication company as the medium of the network to maintain the continuity for network autonomy.
Currently, most important ISPs are located in the United States. If an ISP located in another region provides the content of a US ISP to a client, then the ISP must rent hardware and bandwidth of international communication network to use. Accordingly, for many ISPs the highest cost is the fees for using the international network bandwidth.
Here is a simple example. Referring to FIG. 1, ISP A and ISP B are located in different locations, wherein ISP A mainly provides clients with the services of using the network, while ISP B provides ICPs (Internet Content Providers) with the services for managing the hosts. The main cost for both ISP A and ISP B is the fee for using the bandwidth to access the Internet. The income for ISP A is the fees paid by clients. Such income is constant. The income for ISP B is the bandwidth fees paid by ICPs. That is, the more people review the information provided on the hosts, the higher the income of ISP B is.
When a client of ISP A requests a certain information, ISP A sends the request to ISP B, then ISP B sends the requested information to ISP A via the internet, so that ISP A can provide the same to the client. When another client requests the same information, or the same client requests the same information again, the requesting and sending steps mentioned above are operated once more. Accordingly, the same information is transmitted over the Internet many times, which causes a waste for use of bandwidth. In addition, ISP A has to pay the fee for using bandwidth to transmit the same information again and again.
Referring to FIG. 2, ISP A may set a cache server at the bandwidth outlet thereof to store the caught information contents. When an information content is requested by the client, ISP A can first search the cache server for the information. If the information is found, ISP A provides the same to the client directly. If the information is not found, then ISP A sends a request to ISP B for the required information content. By this way, the cost for ISP A can be lowered. However, such a method causes a loss to ISP B, since the number of times that ISP B needs to transmit the information contents managed for ICPs is significantly lowered. Therefore, if ISP A takes such a scheme, ISP A is in benefit conflict with other ISPs.
Therefore, solutions to solve the above problems are required. The present invention provides such a solution.
An objective of the present invention is to provide a content delivery network system, which can solve the continuity problem for the individual autonomous network, so as to extend the individual network. Another objective of the present invention is to provide a content delivery network system to solve the problem for site proximity, so as to ensure that the information content reaches the nearest cache server via the shortest route.
A further objective of the present invention is to provide a content delivery network system, by which the ISP providing the services for clients to access the Internet can reduce the use of international network bandwidth, thereby lowering the cost while maintaining the service quality of providing information. In addition, the income for the ISP managing the hosts will not be reduced.
Still a further objective of the present invention is to provide a billing system to calculate the fees for providing clients with information not via the international network bandwidth, so that the ISP providing the services for clients to access the Internet and the ISP managing the hosts can reasonably share the benefit from saving the cost of using bandwidth.
According to an aspect of the present invention, a content delivery network system comprises a communication network, a first network node for providing services for clients to access network, a second network node for managing hosts and a third network node, wherein said third network node sets a default route and a VPN tunnel between the first and second network nodes, and provides a cache server at the bandwidth outlet of the first network node, said cache server storing an information content which has been requested and transmitted, when the client request an information content, the third network node searches the cache server, if the information content is found, the cache server provides said information content to the client directly, if the information content is not found, the cache server sends a request for catching the information content to the second network via the VPN tunnel, and takes the information content to transmit the same to the client via the default route, and the cache server records the host data which provides the information content, the recorded data is provided to the second network node, so that the second network node can bill the owner of the host accordingly.
According to another aspect of the present invention, a method for delivering content over network comprising steps of building a communication network; building a first network node for providing clients with network accessing services; building a second network node for providing information from network content providers; setting a default route via the communication network and a VPN tunnel between the first and second network nodes, and providing, at the communication outlet of the first network node, a cache server for storing information contents transmitted from the second network node; when a client of the first network node requests a certain information content, searching the cache server and providing to the client if said information content is found; if said information content is not found, sending a request for catching said information content to the second network node; transmitting said information content via the default route by the second network node to said cache server; storing said information content and providing the same to the client; recording data of said transmitted information content and providing the recorded data to the second network node, so that the second network node can bill the network content providers.
According to a further aspect of the present invention, a method for building a content delivering network system comprising steps of building a communication network between a first network node for providing clients with network accessing services and a second network node for managing hosts; setting routes between the first and second network nodes, said routes including a default route and a VPN tunnel; establishing iBGP switching between the first and second network nodes; providing a cache server at the first network node; performing redirection to force all the communicated contents to pass said cache server; and taking required information contents from the hosts managed by the second network node and storing in said cache server for use.
According to still another aspect, in the network system of the present invention, the cache server is provided with a billing system, wherein the cache server records data of transmitted information including the traffic and the spent time of the information contents transmitted from each host to calculate the average bandwidth used amount, and the traffics of all the hosts are summed to get a sum. Said sum and the highest used bandwidth are calculated to get a factor. The maximum bandwidth used amount during a certain period is obtained by multiplying the average traffic of each host by said factor.